The use of fire suppression and detection systems has become widespread in both industrial and residential fields. These systems are provided for fixed installation and mobile installation.
One method of detecting the presence of heat/fire is the use of tubing positioned in the area to be surveyed. Such tubing may be metal piping or plastic. When heat or fire is sensed, the integrity of the tubing, which contains a pressurized fluid, is interrupted either by a melt-down of the tube itself or a sensing element. The loss of pressure in the tube is thereafter utilized as a control variable for actuating warning devices, fire suppression systems and the like.
Certain criteria are desirable for the devices which sense the pressure loss in the surveillance tubing which have not altogether been met in the industry, particularly in mobile sensing systems. These criteria include: (a) the device should be fully self-contained and require no external power source; (b) the device should be able to sense a fire or high temperature condition and then actuate a fire suppression system; (c) the device should be fail-safe; that is, no part of the mechanism must be capable of preventing actuation in the event of a high temperature or fire condition; and (d) the device should be able to withstand the extreme shock and vibration of a mobile vehicle environment.